From DOS/Windows to Linux HOWTO
By Guido Gonzato, ggonza at tin.it
Version 1.3.5. 31 August 2000.
This HOWTO is dedicated to all the (soon to be former?) DOS and Win­
dows users who have decided to switch to Linux, the free UNIX clone.
The purpose of this document is to help the reader translate his or
her knowledge of DOS and Windows into the Linux environment, as well
as providing hints on exchanging files and resources between the two
OSes.
______________________________________________________________________
Table of Contents
1. Introduction
1.1 Is Linux Right for You?
1.2 It Is. Tell Me More
1.2.1 Introductory Concepts
1.2.2 Getting Help
1.3 Conventions
2. For the Impatient
3. Meet bash
4. Files and Programs
4.1 Files: Preliminary Notions
4.2 Symbolic Links
4.3 Permissions and Ownership
4.4 Files: Translating Commands
4.4.1 Examples
4.5 Running Programs: Multitasking and Sessions
4.6 Running Programs on Remote Computers
5. Using Directories
5.1 Directories: Preliminary Notions
5.2 Directories Permissions
5.3 Directories: Translating Commands
5.3.1 Examples
6. Floppies, Hard Disks, and the Like
6.1 Managing Devices the DOS Way
6.2 Managing Devices the UNIX Way
6.3 Backing Up
7. What About Windows?
8. Tailoring the System
8.1 System Initialisation Files
8.2 Program Initialisation Files
9. Networking: Concepts
10. A Bit of Programming
10.1 Shell Scripts: .BAT Files on Steroids
10.2 C for Yourself
10.3 X11 Programming
10.3.1 Multi-Platform Programming
11. The Remaining 1%
11.1 Running DOS/Windows Apps
11.2 Using tar and gzip
11.3 Installing Applications
11.4 Tips You Can't Do Without
11.5 Where to Find Applications
11.6 A Few Things You Couldn't Do
11.7 Practicing UNIX under DOS/Win
11.8 Common Extensions and Related Programs
11.9 Converting Files
11.10 Free Office Suites
12. The End, for Now
12.1 Copyright
12.2 Disclaimer
______________________________________________________________________
1. Introduction
1.1. Is Linux Right for You?
Let's start politically correct. Throughout this document I say
``Linux'', but I mean ``GNU/Linux''. Please go to
to see why.
You want to switch from the DOS/Windows world to Linux? Good idea:
Linux is technically superior to DOS, Windows 9x and even Windows NT.
But beware: it might not be useful for you. These are the main
differences between DOS/Windows and Linux:
· Windows runs Microsoft Office and lots of games; is perceived to be
easy to install and configure; is notoriously unstable; performs
poorly; crashes are frequent.
· Linux runs StarOffice, scores of technical software and fewer
games; can be tricky to install and configure; is rock solid;
performs impeccably; crashes are extremely rare.
It's up to you to decide what you need. Furthermore, Linux gives you
power, but it takes some time to learn how to harness it. Thus, if
mostly need commercial sw, or if you don't feel like learning new
commands and concepts, you had better look elsewhere. Be aware that
many newcomers give up because of initial difficulties.
Work is underway to make Linux simpler to use, but don't expect to be
proficient with it unless you read a lot of documentation and use it
at least for a few months. Linux won't give you instant results. In
spite of these warnings, I'm 100% confident that if you are the right
user type you'll find in Linux your computer Nirvana. By the way,
Linux + DOS/Win can coexist happily on the same machine.
Prerequisites for this howto: I'll assume that
· you know the basic DOS commands and concepts;
· Linux, possibly with X Window System (X11 for short), is properly
installed on your PC;
· your shell (the equivalent of COMMAND.COM) is bash.
Unless specified, all information in this work is aimed at bad ol'
DOS. There is information about Windows here and there, but bear in
mind that Windows and Linux are totally different, unlike DOS that is
sort of a UNIX poor relation.
Please also note that this work is neither a complete primer nor a
configuration guide!
The latest version of this document is available in several formats on
.
1.2. It Is. Tell Me More
You installed Linux and the programs you needed on the PC. You gave
yourself an account (if not, type adduser yourname now!) and Linux is
running. You've just entered your name and password, and now you are
looking at the screen thinking: ``Well, now what?''
Now, don't despair. You're almost ready to do the same things you used
to do with DOS/Win, and many more. If you were running DOS/Win instead
of Linux, you would be doing some of the following tasks:
· running programs and creating, copying, viewing, deleting,
printing, renaming files;
· CD'ing, MD'ing, RD'ing, and DIR'ring your directories;
· formatting floppies and copying files from/to them;
· tailoring the system;
· surfing the Internet;
· writing .BAT files and programs in your favourite language;
· the remaining 1%.
You'll be glad to know that these tasks can be accomplished under
Linux in a fashion similar to DOS. Under DOS, the average user uses
very few of the 100+ commands available: the same, up to a point,
applies to Linux.
1.2.1. Introductory Concepts
The best way to learn something new is to get your feet wet. You are
strongly encouraged to experiment and play with Linux: unless you
login as ``root'', you can't damage the system that way. A few points:
· first of all, how to quit Linux safely. If you see a text mode
screen, press , wait for the system to reboot, then
switch off the PC. If you are working under X Window System, press
first, then . Never switch off
or reset the PC directly: this could damage the file system;
· unlike DOS or Windows, Linux has built-in security mechanisms.
Files and directories have permissions associated to them; as a
result, some cannot be accessed by the normal user; (see Section
``Permissions and Ownership''). DOS and Windows, on the contrary,
will let you wipe out the entire contents of your hard disk;
· there's a special user called ``root'': the system administrator,
with full power of life and death on the machine. If you work on
your own PC, you'll be root as well. Working as root is dangerous:
any mistake can seriously damage or destroy the system just like
with DOS/Windows. Don't work as root unless absolutely necessary;
· much of the complexity of Linux comes from its extreme
configurability: virtually every feature and every application can
be tailored through one or more configuration files. Complexity is
the price to pay for power;
· redirection and piping are a side DOS feature, a very inportant one
and much more powerful under Linux. Simple commands can be strung
together to accomplish complex tasks. I strongly suggest that you
learn how to use them.
1.2.2. Getting Help
There are many ways to get help with Linux. The most important are:
· reading the documentation---I mean it. Although the HOWTO you are
reading may serve as an introduction to Linux, there are several
books that you really should read: at least, Matt Welsh's ``Linux
Installation and Getting Started'' (
) and the Linux FAQ (
). Feel a guilty
conscience until you have read at least one of them;
· the documentation of the packages installed on the machine is often
found in subdirectories under /usr/doc/;
· to get some help about the ``internal commands'' of the shell, type
help or, better, man bash or info bash;
· to get help about a command, type man command that invokes the
manual (``man'') page of command. Alternatively, type info command
that invokes, if available, the info page pertinent of command;
info is a hypertext-based documentation system, perhaps not
intuitive to use at first. Finally, you may try apropos command or
whatis command. With all of these commands, press `q' to exit.
· finally, on the Internet: the right place for getting help is
Usenet, like . Please don't email me for
help, because I'm quite overloaded.
1.3. Conventions
Throughout this work, examples will often follow the following format:
is a required argument, while [...] an optional one. Example:
$ tar -tf [> redir_file]
file.tar must be indicated, but redirection to redir_file is optional.
``RMP'' means ``please Read the Man Pages for further information''. I
can't stress enough how important reading the documentation is.
When the prompt of a command example is #, the command can only be
performed by root.
2. For the Impatient
Want to strike out? Have a look at this table:
DOS Linux Notes
------------------------------------------------------------------------------
ATTRIB (+-)attr file chmod file completely different
BACKUP tar -Mcvf device dir/ ditto
CD dirname\ cd dirname/ almost the same syntax
COPY file1 file2 cp file1 file2 ditto
DEL file rm file beware - no undelete
DELTREE dirname rm -R dirname/ ditto
DIR ls not exactly the same syntax
DIR file /S find . -name file completely different
EDIT file vi file I think you won't like it
jstar file feels like dos' edit
EDLIN file ed file forget it
FORMAT fdformat,
mount, umount quite different syntax
HELP command man command, same philosophy
info command
MD dirname mkdir dirname/ almost the same syntax
MORE < file less file much better
MOVE file1 file2 mv file1 file2 ditto
NUL /dev/null ditto
PRINT file lpr file ditto
PRN /dev/lp0,
/dev/lp1 ditto
RD dirname rmdir dirname/ almost the same syntax
REN file1 file2 mv file1 file2 not for multiple files
RESTORE tar -Mxpvf device different syntax
TYPE file less file much better
WIN startx poles apart!
If you need more than a table of commands, please refer to the
following sections.
3. Meet bash
Good news: with Linux you type much less at the prompt, because the
bash shell types for you whenever possible, and features cool line
editing capabilities. To begin with, the arrow-up key recalls previous
command lines; but there's more. Pressing completes file and
directory names, so typing
$ ls /uTABloTABbTAB
is like typing
$ ls /usr/local/bin
If there were ambiguities, as typing
$ ls /uTABloTABiTAB
bash stops because it doesn't know if you mean /usr/local/info or
/usr/local/include. Supply more characters then press again.
Other useful key presses are that deletes a word to
the left, while deletes a word to the right; moves the
cursor one word to the right, to the left; moves to
the beginning of the line, to the end. The key is
equivalent to .
Enough for now. Once you get used to these shortcuts, you'll find the
DOS prompt very annoying...
4. Files and Programs
4.1. Files: Preliminary Notions
Linux has a structure of directories and files very similar to that of
DOS/Win. Files have filenames that obey special rules, are stored in
directories, some are executable, and among these most have command
switches. Moreover, you can use wildcard characters, redirection, and
piping. There are only a few minor differences:
· under DOS, file names are in the so-called 8.3 form; e.g.
NOTENOUG.TXT. Under Linux we can do better. If you installed Linux
using a file system like ext2 or umsdos, you can use longer
filenames (up to 255 characters), and with more than one dot: for
example, This_is.a.VERY_long.filename. Please note that I used both
upper and lower case characters: in fact...
· upper and lower case characters in file names or commands are
different. Therefore, FILENAME.tar.gz and filename.tar.gz are two
different files. ls is a command, LS is a mistake;
· Windows users, beware when using long file names under Linux. If a
file name contains spaces (not recommended but possible), you must
enclose the file name in double quotes whenever you refer to it.
For example:
$ # the following command makes a directory called "My old files"
$ mkdir "My old files"
$ ls
My old files bin tmp
Further, some characters shouldn't be used: some of those are !*$.
· there are no compulsory extensions like .COM and .EXE for programs,
or .BAT for batch files. Executable files are marked by an asterisk
`*' at the end of their name when you issue the ls -F command. For
example:
$ ls -F
I_am_a_dir/ cindy.jpg cjpg* letter_to_Joe my_1st_script* old~
The files cjpg* and my_1st_script* are executables, that is ``pro­
grams''. Under DOS, backup files end in .BAK, while under Linux they
end with a tilde `~'. Further, a file whose name starts with a dot is
considered as hidden. Example: the file .I.am.a.hidden.file won't show
up after the ls command;
· DOS program switches are obtained with /switch, Linux switches with
-switch or --switch. Example: dir /s becomes ls -R. Note that
many DOS programs, like PKZIP or ARJ, use UNIX-style switches.
You can now jump to Section ``Translating Commands from DOS to
Linux'', but if I were you I'd read on.
4.2. Symbolic Links
UNIX has a type of file that doesn't exist under DOS: the symbolic
link. This can be thought of as a pointer to a file or to a
directory, and can be used instead of the file or directory it points
to; it's similar to Windows shortcuts. Examples of symbolic links are
/usr/X11, which points to /usr/X11R6; /dev/modem, which points to
either /dev/ttyS0 or /dev/ttyS1.
To make a symbolic link:
$ ln -s
Example:
$ ln -s /usr/doc/g77/DOC g77manual.txt
Now you can refer to g77manual.txt instead of /usr/doc/g77/DOC. Links
appear like this in directory listings:
$ ls -F
g77manual.txt@
$ ls -l
(several things...) g77manual.txt -> /usr/doc/g77/DOC
4.3. Permissions and Ownership
DOS files and directories have the following attributes: A (archive),
H (hidden), R (read-only), and S (system). Only H and R make sense
under Linux: hidden files start with a dot, and for the R attribute,
read on.
Under UNIX a file has ``permissions'' and an owner, who in turn
belongs to a ``group''. Look at this example:
$ ls -l /bin/ls
-rwxr-xr-x 1 root bin 27281 Aug 15 1995 /bin/ls*
The first field contains the permissions of the file /bin/ls, which
belongs to root, group bin. Leaving the remaining information aside,
remember that -rwxr-xr-x means, from left to right:
- is the file type (- = ordinary file, d = directory, l = link, etc);
rwx are the permissions for the file owner (read, write, execute); r-x
are the permissions for the group of the file owner (read, execute);
(I won't cover the concept of group, you can survive without it as
long as you're a beginner ;-) r-x are the permissions for all other
users (read, execute).
The directory /bin has permissions, too: see Section ``Directories
Permissions'' for further details. This is why you can't delete the
file /bin/ls unless you are root: you don't have the permission to do
so. To change a file's permissions, the command is:
$ chmod
where who is u (user, that is owner), g (group), o (other), X is
either + or -, perm is r (read), w (write), or x (execute). Common
examples of chmod use are the following:
$ chmod +x file
this sets the execute permission for the file.
$ chmod go-rw file
this removes read and write permission for everyone but the owner.
$ chmod ugo+rwx file
this gives everyone read, write, and execute permission.
# chmod +s file
this makes a so-called ``setuid'' or ``suid'' file---a file that
everyone can execute with its owner's privileges. Typically, you'll
come across root suid files; these are often important system files,
like the X server.
A shorter way to refer to permissions is with digits: rwxr-xr-x can be
expressed as 755 (every letter corresponds to a bit: --- is 0, --x is
1, -w- is 2, -wx is 3...). It looks difficult, but with a bit of
practice you'll understand the concept. root, being the superuser, can
change everyone's file permissions. RMP.
4.4. Files: Translating Commands
On the left, the DOS commands; on the right, their Linux counterpart.
ATTRIB: chmod
COPY: cp
DEL: rm
MOVE: mv
REN: mv
TYPE: more, less, cat
Redirection and plumbing operators: < > >> |
Wildcards: * ?
nul: /dev/null
prn, lpt1: /dev/lp0 or /dev/lp1; lpr
4.4.1. Examples
DOS Linux
---------------------------------------------------------------------
C:\GUIDO>ATTRIB +R FILE.TXT $ chmod 400 file.txt
C:\GUIDO>COPY JOE.TXT JOE.DOC $ cp joe.txt joe.doc
C:\GUIDO>COPY *.* TOTAL $ cat * > total
C:\GUIDO>COPY FRACTALS.DOC PRN $ lpr fractals.doc
C:\GUIDO>DEL TEMP $ rm temp
C:\GUIDO>DEL *.BAK $ rm *~
C:\GUIDO>MOVE PAPER.TXT TMP\ $ mv paper.txt tmp/
C:\GUIDO>REN PAPER.TXT PAPER.ASC $ mv paper.txt paper.asc
C:\GUIDO>PRINT LETTER.TXT $ lpr letter.txt
C:\GUIDO>TYPE LETTER.TXT $ more letter.txt
C:\GUIDO>TYPE LETTER.TXT $ less letter.txt
C:\GUIDO>TYPE LETTER.TXT > NUL $ cat letter.txt > /dev/null
n/a $ more *.txt *.asc
n/a $ cat section*.txt | less
Notes:
· * is smarter under Linux: * matches all files except the hidden
ones; .* matches all hidden files (but also the current directory
`.' and parent directory `..': beware!); *.* matches only those
that have a `.' in the middle or that end with a dot; p*r matches
both `peter' and `piper'; *c* matches both `picked' and `peck';
· when using more, press to read through the file, `q' to
exit. less is more intuitive and lets you use the arrow keys;
· there is no UNDELETE, so think twice before deleting anything;
· in addition to DOS' < > >>, Linux has 2> to redirect error messages
(stderr); moreover, 2>&1 redirects stderr to stdout, while 1>&2
redirects stdout to stderr;
· Linux has another wildcard: the []. Usage: [abc]* matches files
starting with a, b, c; *[I-N1-3] matches files ending with I, J, K,
L, M, N, 1, 2, 3;
· lpr prints a file in background. To check the status of the
print queue, use lpq; to remove a file from the print queue, use
lprm;
· there is no DOS-like RENAME; that is, mv *.xxx *.yyy won't work. A
REN-like command is available on
;
· use cp -i and mv -i to be warned when a file is going to be
overwritten.
4.5. Running Programs: Multitasking and Sessions
To run a program, type its name as you would do under DOS. If the
directory (Section ``Using Directories'') where the program is stored
is included in the PATH (Section ``System Initialisation Files''), the
program will start. Exception: unlike DOS, under Linux a program
located in the current directory won't run unless the directory is
included in the PATH. Escamotage: being prog your program, type
./prog.
This is what the typical command line looks like:
$ command [-s1 [-s2] ... [-sn]] [par1 [par2] ... [parn]] [< input] [> output]
where -s1, ..., -sn are the program switches, par1, ..., parn are the
program parameters. You can issue several commands on the command
line:
$ command1 ; command2 ; ... ; commandn
That's all about running programs, but it's easy to go a step beyond.
One of the main reasons for using Linux is that it is a multitasking
os---it can run several programs (from now on, processes) at the same
time. You can launch processes in background and continue working
straight away. Moreover, Linux lets you have several sessions: it's
like having many computers to work on at once!
· To switch to session 1..6 on the virtual consoles, press
...
· To start a new session in the same v.c. without leaving the current
one, type su - . Example: su - root. This is useful, for
instance, when you need to perform a task that only root can do.
· To end a session, type exit. If there are stopped jobs (see later),
you'll be warned.
· To launch a process in background, add an ampersand '&' at the end
of the command line:
$ progname [-switches] [parameters] [< input] [> output] &
[1] 123
the shell identifies the process with a job number (e.g. [1]; see
below), and with a PID (Process Identification Number; 123 in our
example).
· To see how many processes there are, type ps ax. This will output a
list of currently running processes.
· To kill (terminate) a process, type kill . You may need to
kill a process when you don't know how to quit it the right way....
Unless you're root, you can't kill other people's processes.
Sometimes, a process will only be killed by kill -SIGKILL .
In addition, the shell allows you to stop or temporarily suspend a
process, send a process to background, and bring a process from
background to foreground. In this context, processes are called
``jobs''.
· To see how many jobs there are, type jobs. Here the jobs are
identified by their job number, not by their PID.
· To stop a process running in foreground, press (it won't
always work).
· To suspend a process running in foreground, press (ditto).
· To send a suspended process into background, type bg (it
becomes a job).
· To bring a job to foreground, type fg . To bring to
foreground the last job sent to background, simply type fg.
· To kill a job, type kill where may be 1, 2, 3,...
Using these commands you can format a disk, zip a bunch of files,
compile a program, and unzip an archive all at the same time, and
still have the prompt at your disposal. Try this with Windows, just to
see the difference in performance (if it doesn't crash, of course).
4.6. Running Programs on Remote Computers
To run a program on a remote machine whose name is remote.machine.edu:
$ telnet remote.machine.edu
After logging in, start your favourite program. Needless to say, you
must have a shell account on the remote machine.
If you have X11, you can even run an X application on a remote
computer, displaying it on your X screen. Let remote.machine.edu be
the remote X computer and let local.linux.box be your Linux machine.
To run from local.linux.box an X program that resides on
remote.machine.edu, do the following:
· fire up X11, start an xterm or equivalent terminal emulator, then
type:
$ xhost +remote.machine.edu
$ telnet remote.machine.edu
· after logging in, type:
remote:$ DISPLAY=local.linux.box:0.0
remote:$ progname &
(instead of DISPLAY..., you may have to write: setenv DISPLAY
local.linux.box:0.0. It depends on the remote shell.)
Et voila! Now progname will start on remote.machine.edu and will be
displayed on your machine. Don't try this over the modem though, for
it's too slow to be usable. Moreover, this is a crude and insecure
method: please read the ``Remote X Apps mini-HOWTO'' at
.
5. Using Directories
5.1. Directories: Preliminary Notions
We have seen the differences between files under DOS/Win and Linux. As
for directories, under DOS/Win the root directory is \, under Linux it
is /. Similarly, nested directories are separated by \ under DOS/Win,
by / under Linux. Example of file paths:
DOS: C:\PAPERS\GEOLOGY\MID_EOC.TEX
Linux: /home/guido/papers/geology/middle_eocene.tex
As usual, .. is the parent directory and . is the current directory.
Remember that the system won't let you cd, rd, or md everywhere you
want. Each user has his or her stuff in a directory called `home',
given by the system administrator; for instance, on my PC my home dir
is /home/guido.
5.2. Directories Permissions
Directories, too, have permissions. What we have seen in Section
``Permissions and Ownership'' applies to directories as well (user,
group, and other). For a directory, rx means you can cd to that
directory, and w means that you can delete a file in the directory
(according to the file's permissions, of course), or the directory
itself.
For example, to prevent other users from snooping in /home/guido/text:
$ chmod o-rwx /home/guido/text
5.3. Directories: Translating Commands
DIR: ls, find, du
CD: cd, pwd
MD: mkdir
RD: rmdir
DELTREE: rm -rf
MOVE: mv
5.3.1. Examples
DOS Linux
---------------------------------------------------------------------
C:\GUIDO>DIR $ ls
C:\GUIDO>DIR FILE.TXT $ ls file.txt
C:\GUIDO>DIR *.H *.C $ ls *.h *.c
C:\GUIDO>DIR/P $ ls | more
C:\GUIDO>DIR/A $ ls -l
C:\GUIDO>DIR *.TMP /S $ find / -name "*.tmp"
C:\GUIDO>CD $ pwd
n/a - see note $ cd
ditto $ cd ~
ditto $ cd ~/temp
C:\GUIDO>CD \OTHER $ cd /other
C:\GUIDO>CD ..\TEMP\TRASH $ cd ../temp/trash
C:\GUIDO>MD NEWPROGS $ mkdir newprogs
C:\GUIDO>MOVE PROG .. $ mv prog ..
C:\GUIDO>MD \PROGS\TURBO $ mkdir /progs/turbo
C:\GUIDO>DELTREE TEMP\TRASH $ rm -rf temp/trash
C:\GUIDO>RD NEWPROGS $ rmdir newprogs
C:\GUIDO>RD \PROGS\TURBO $ rmdir /progs/turbo
Notes:
· when using rmdir, the directory to remove must be empty. To delete
a directory and all of its contents, use rm -rf (at your own risk).
· the character `~' is a shortcut for the name of your home
directory. The commands cd or cd ~ will take you to your home
directory from wherever you are; the command cd ~/tmp will take you
to /home/your_home/tmp.
· cd - ``undoes'' the last cd.
6. Floppies, Hard Disks, and the Like
There are two ways to manage devices under Linux: the DOS way and the
UNIX way. Take your pick.
6.1. Managing Devices the DOS Way
Most Linux distributions include the Mtools suite, a set of commands
that are perfectly equivalent to their DOS counterpart, but start with
an `m': i.e., mformat, mdir, mdel, mmd, and so on. They can even
preserve long file names, but not file permissions. If you configure
Mtools editing a file called /etc/mtools.conf (a sample is provided in
the distribution), you can also access the DOS/Win partition, the
CD--ROM, and the Zip drive. To format a fresh disk though, the mformat
command won't do. As root, you'll have to issue this command
beforehand: fdformat /dev/fd0H1440.
You can't access files on the floppy with a command like, say, less
a:file.txt! This is the disadvantage of the DOS way of accessing
disks.
6.2. Managing Devices the UNIX Way
UNIX has a different way to handle devices. There are no separate
volumes like A: or C:; a disk, be it a floppy or whatever, becomes
part of the local file system through an operation called
``mounting''. When you're done using the disk, before extracting it
you must ``unmount'' it.
Physically formatting a disk is one thing, making a file system on it
is another. The DOS command FORMAT A: does both things, but under
Linux there are separate commands. To format a floppy, see above; to
create a file system:
# mkfs -t ext2 -c /dev/fd0H1440
You can use dos, vfat (recommended) or other formats instead of ext2.
Once the disk is prepared, mount it with the command
# mount -t ext2 /dev/fd0 /mnt
specifying the right file system if you don't use ext2. Now you can
address the files in the floppy using /mnt instead of A: or B:.
Examples:
DOS Linux
---------------------------------------------------------------------
C:\GUIDO>DIR A: $ ls /mnt
C:\GUIDO>COPY A:*.* $ cp /mnt/* .
C:\GUIDO>COPY *.ZIP A: $ cp *.zip /mnt
C:\GUIDO>EDIT A:FILE.TXT $ jstar /mnt/file.txt
C:\GUIDO>A: $ cd /mnt
A:> _ /mnt/$ _
When you've finished, before extracting the disk you must unmount it
with the command
# umount /mnt
Obviously, you have to fdformat and mkfs only unformatted disks, not
previously used ones. If you want to use the drive B:, refer to
fd1H1440 and fd1 instead of fd0H1440 and fd0 in the examples above.
Needless to say, what applies to floppies also applies to other
devices; for instance, you may want to mount another hard disk or a
CD--ROM drive. Here's how to mount the CD--ROM:
# mount -t iso9660 /dev/cdrom /mnt
This was the ``official'' way to mount your disks, but there's a trick
in store. Since it's a bit of a nuisance having to be root to mount a
floppy or a CD--ROM, every user can be allowed to mount them this way:
· as root, do the following:
# mkdir /mnt/floppy ; mkdir /mnt/cdrom
# chmod 777 /mnt/floppy /mnt/cd*
# # make sure that the CD-ROM device is right
# chmod 666 /dev/hdb ; chmod 666 /dev/fd*
· add in /etc/fstab the following lines:
/dev/cdrom /mnt/cdrom iso9660 ro,user,noauto 0 0
/dev/fd0 /mnt/floppy vfat user,noauto 0 0
Now, to mount a DOS floppy and a CD--ROM:
$ mount /mnt/floppy
$ mount /mnt/cdrom
/mnt/floppy and /mnt/cdrom can now be accessed by every user. Remember
that allowing everyone to mount disks this way is a gaping security
hole, if you care.
Two useful commands are df, which gives information on the mounted
file systems, and du dirname which reports the disk space consumed by
the directory.
6.3. Backing Up
There are several packages to help you, but the very least you can do
for a multi-volume backup is (as root):
# tar -M -cvf /dev/fd0H1440 dir_to_backup/
Make sure to have a formatted floppy in the drive, and several more
ready. To restore your stuff, insert the first floppy in the drive
and do:
# tar -M -xpvf /dev/fd0H1440
7. What About Windows?
The ``equivalent'' of Windows is the graphic system X Window System.
Unlike Windows or the Mac, X11 wasn't designed for ease of use or to
look good, but just to provide graphic facilities to UNIX
workstations. These are the main differences:
· while Windows looks and feels the same all over the world, X11 does
not: it's much more configurable. X11's overall look is given by a
key component called ``window manager'', of which you have a wide
choice: fvwm, basic but nice and memory efficient, fvwm2-95,
Afterstep, WindowMaker, Enlightenment, and many more. The w.m. is
usually invoked from .xinitrc;
· your w.m. can be configured so as a window acts as under, er,
Windows: you click on it and it comes to foreground. Another
possibility is that it comes to foreground when the mouse moves
over it (``focus''). Also, the placement of windows on the screen
can be automatic or interactive: if a strange frame appears instead
of your program, left click where you want it to appear;
· most features can be tailored editing one or more configuration
files. Read the docs of your w.m.: the configuration file can be
.fvwmrc, .fvwm2rc95, .steprc, etc. A sample configuration file is
typically found in /etc/X11/window-manager-name/system.window-
manager-name;
· X11 applications are written using special libraries (``widget
sets''); as several are available, applications look different. The
most basic ones are those that use the Athena widgets (2--D look;
xdvi, xman, xcalc); others use Motif (netscape), others still use
Tcl/Tk, Qt, Gtk, XForms, and what have you. Nearly all of these
libraries provide roughly the same look and feel as Windows;
· the feel, unfortunately, can be incoherent. For instance, if you
select a line of text using the mouse and press , you'd
expect the line to disappear, right? This won't work with
Athena--based apps, but it does with other widget sets;
· how scrollbars and resizing work depends on the w.m. and the widget
set. Tip: if you find that the scrollbars don't behave as you would
expect, try using the central button or the two buttons together to
move them;
· applications don't have an icon by default, but they can have many.
Most w.m. feature a menu you recall by clicking on the desktop
(``root window''); needless to say, the menu can be tailored. To
change the root window appearance, use xsetroot or xloadimage;
· the clipboard can only contain text, and behaves strange. Once
you've selected text, it's already copied to the clipboard: move
elsewhere and press the central button to paste it. There's an
application, xclipboard, that provides for multiple clipboard
buffers;
· drag and drop is an option, and is only available if you use X11
applications and/or w.m. that support it.
This said, good news for you. There are projects that aim at making
X11 look and behave as coherently as Windows. Gnome,
, and KDE, , are simply
awesome. Most likely your distribution uses either or both. You won't
regret your Windows desktop anymore!
8. Tailoring the System
8.1. System Initialisation Files
Two important files under DOS are AUTOEXEC.BAT and CONFIG.SYS, which
are used at boot time to initialise the system, set some environment
variables like PATH and FILES, and possibly launch a program or batch
file. Additionally, Windows has the infamous registry---one of the
worst ideas ever conceived in computer science.
Under Linux there are lots of initialisation files, some of which you
had better not tamper with until you know exactly what you are doing;
they reside in the /etc tree. All configuration can be done editing
plain text files. If all you need is setting the PATH and other
environment variables, or you want to change the login messages or
automatically launch a program on login, have a look at the following
files:
FILES NOTES
/etc/issue sets pre-login message
/etc/motd sets post-login message
/etc/profile sets $PATH and other variables, etc.
/etc/bashrc sets aliases and functions, etc.
/home/your_home/.bashrc sets your aliases + functions
/home/your_home/.bash_profile or
/home/your_home/.profile sets environment + starts your progs
If the latter file exists (note that it is a hidden file), it will be
read after the login, and the commands therein will be executed.
Example---look at this .bash_profile:
______________________________________________________________________
# I am a comment
echo Environment:
printenv | less # equivalent of command SET under DOS
alias d='ls -l' # easy to understand what an alias is
alias up='cd ..'
echo "I remind you that the path is "$PATH
echo "Today is `date`" # use the output of the command 'date'
echo "Have a good day, "$LOGNAME
# The following is a "shell function"
ctgz() # List the contents of a .tar.gz archive.
{
for file in $*
do
gzip -dc ${file} | tar tf -
done
}
# end of .profile
______________________________________________________________________
$PATH and $LOGNAME, you guessed right, are environment variables.
There are many others to play with; for instance, RMP for apps like
less or bash.
Putting this line in your /etc/profile will provide the rough
equivalent of PROMPT $P$G:
export PS1="\w\\$ "
8.2. Program Initialisation Files
Under Linux, virtually everything can be tailored to your needs. Most
programs have one or more initialisation files you can fiddle with,
often as a .prognamerc in your home dir. The first ones you'll want to
modify are:
· .inputrc: used by bash to define key bindings;
· .xinitrc: used by startx to initialise X Window System;
· .fvwmrc: used by the window manager fvwm.
· .joerc, .jstarrc: used by the editor joe;
· .jedrc: used by the editor jed;
· .pinerc: used by the mail reader pine;
· .Xdefault: used by many X programs.
For all of these and the others you'll come across sooner or later,
RMP. Perhaps I could interest you in the Configuration HOWTO,
?
9. Networking: Concepts
Not only is ``Dialup Networking'' available under Linux, it's also
more stable and quicker. The name of the game is ``PPP'', the protocol
employed for connecting to the Internet using modems. All you need is
a tool that dials out and makes the connection.
To retrieve your mail from the ISP's server you need a tool called
``email fetcher'' that uses the POP protocol; when the mail is fetched
it will appear as though it had been directly delivered to your Linux
box. You'll then use a MUA (Mail User Agent) like pine, mutt, elm or
many others to manage it.
While under Windows the dialer is automatically invoked when you
launch an Internet application, under Linux the path is the other way
round: you dial first, then launch the application. A thing called
diald provides the usual behaviour. Installing and configuring dialup
networking used to be one of the most difficult things to do under
Linux, but not anymore: please consult the Configuration HOWTO.
Finally, a word about ``Network neighborhood'': you can make your
Linux workstation appear as Windows NT/9x in a local network of
Windows machines! The magic word is Samba: not the lively Brazilian
dance, but an implementation of the SMB protocol for Linux. Go to
.
10. A Bit of Programming
10.1. Shell Scripts: .BAT Files on Steroids
If you used .BAT files to create shortcuts of long command lines (I
did a lot), this goal can be attained by inserting appropriate alias
lines (see example above) in profile or .bash_profile. But if your
.BATs were more complicated, then you'll love the scripting language
made available by the shell: it's as powerful as good ol' QBasic, if
not more. It has variables, structures like while, for, case, if...
then... else, and lots of other features: it can be a good alternative
to a ``real'' programming language.
To write a script---the equivalent of a .BAT file under DOS---all you
have to do is write a standard ASCII file containing the instructions,
save it, then make it executable with the command chmod +x
. To execute it, type its name.
A word of warning. The system editor is called vi, and in my
experience most new users find it very difficult to use. I'm not going
to explain how to use it; please consult Matt Welsh's book or search
for a tutorial on the net. Suffice it here to say that:
· to insert some text, type i then your text;
· to delete characters, type then x;
· to quit vi whithout saving, type then :q!
· to save and quit, type then :wq.
A good beginner editor is joe: invoking it by typing jstar you'll get
the same key bindings as the DOS/Win editor. jed in WordStar or IDE
mode is even better. Please consult Section ``Where to Find
Applications'' to see where to get these editors.
Writing scripts under bash is such a vast subject it would require a
book by itself, and I will not delve into the topic any further. I'll
just give you an example of shell script, from which you can extract
some basic rules:
______________________________________________________________________
#!/bin/sh
# sample.sh
# I am a comment
# don't change the first line, it must be there
echo "This system is: `uname -a`" # use the output of the command
echo "My name is $0" # built-in variables
echo "You gave me the following $# parameters: "$*
echo "The first parameter is: "$1
echo -n "What's your name? " ; read your_name
echo notice the difference: "hi $your_name" # quoting with "
echo notice the difference: 'hi $your_name' # quoting with '
DIRS=0 ; FILES=0
for file in `ls .` ; do
if [ -d ${file} ] ; then # if file is a directory
DIRS=`expr $DIRS + 1` # DIRS = DIRS + 1
elif [ -f ${file} ] ; then
FILES=`expr $FILES + 1`
fi
case ${file} in
*.gif|*jpg) echo "${file}: graphic file" ;;
*.txt|*.tex) echo "${file}: text file" ;;
*.c|*.f|*.for) echo "${file}: source file" ;;
*) echo "${file}: generic file" ;;
esac
done
echo "there are ${DIRS} directories and ${FILES} files"
ls | grep "ZxY--%%WKW"
if [ $? != 0 ] ; then # exit code of last command
echo "ZxY--%%WKW not found"
fi
echo "enough... type 'man bash' if you want more info."
______________________________________________________________________
10.2. C for Yourself
Under UNIX, the system language is C, love it or hate it. Scores of
other languages (Java, FORTRAN, Pascal, Lisp, Basic, Perl, awk...) are
also available.
Taken for granted that you know C, here are a couple of guidelines for
those of you who have been spoilt by Turbo C++ or one of its DOS kin.
Linux's C compiler is called gcc and lacks all the bells and whistles
that usually accompany its DOS counterparts: no IDE, on-line help,
integrated debugger, etc. It's just a rough command-line compiler,
very powerful and efficient. To compile your standard hello.c you'll
do:
$ gcc hello.c
which will create an executable file called a.out. To give the
executable a different name, do
$ gcc -o hola hello.c
To link a library against a program, add the switch -l. For
example, to link in the math library:
$ gcc -o mathprog mathprog.c -lm
(The -l switch forces gcc to link the library
/usr/lib/lib.so; so -lm links /usr/lib/libm.so).
So far, so good. But when your prog is made of several source files,
you'll need to use the utility make. Let's suppose you have written an
expression parser: its source file is called parser.c and #includes
two header files, parser.h and xy.h. Then you want to use the routines
in parser.c in a program, say, calc.c, which in turn #includes
parser.h. What a mess! What do you have to do to compile calc.c?
You'll have to write a so-called Makefile, which teaches the compiler
the dependencies between sources and objects files. In our example:
______________________________________________________________________
# This is Makefile, used to compile calc.c
# Press the key where indicated!
calc: calc.o parser.o
gcc -o calc calc.o parser.o -lm
# calc depends on two object files: calc.o and parser.o
calc.o: calc.c parser.h
gcc -c calc.c
# calc.o depends on two source files
parser.o: parser.c parser.h xy.h
gcc -c parser.c
# parser.o depends on three source files
# end of Makefile.
______________________________________________________________________
Save this file as Makefile and type make to compile your program;
alternatively, save it as calc.mak and type make -f calc.mak, and of
course RMP. You can invoke some help about the C functions, that are
covered by man pages, section 3; for example,
$ man 3 printf
To debug your programs, use gdb. info gdb to learn how to use it.
There are lots of libraries available; among the first you may want to
use are ncurses (textmode effects), and svgalib (console graphics).
Many editors can act as an IDE; emacs and jed, for instance, also
feature syntax highlighting, automatic indent, and so on.
Alternatively, get the package rhide from
. It's a Borland
IDE clone, and chances are that you'll like it.
10.3. X11 Programming
If you feel brave enough to tackle X11 programming (it's not that
difficult), there are several libraries that make writing X11 programs
a breeze. The main sites to visit are those of GTK+,
, and Qt, . Gtk+ is a C-
based widget set originally written for the graphic package The GIMP (
), and is used by the Gnome environment.
Kdeveloper is based on C++-based Qt, used by KDE. Most likely, you'll
use one of these.
Some of the best tools for visual programming are Kdevelop for Qt,
, and Glade for GTK+, .
This page has more information: .
10.3.1. Multi-Platform Programming
Wouldn't it be nice if you could write code that compiled seamlessly
under Linux and Windows using gcc? As of this writing, there are some
widget sets that allow for more-or-less stable multi-platform
programming. As far as stability and completeness are concerned
though, I would say that the choice is narrowed down to only one:
FLTK, the Fast Light Tool Kit . It's amazingly
small, quick, and stable. It also has a semi-visual builder called
Fluid.
11. The Remaining 1%
Much more than 1%, actually...
11.1. Running DOS/Windows Apps
Yes, you can to some extent run DOS and Windows applications under
Linux! There are two emulators that are quite good: Dosemu (
) and Wine ( ). The
latter is getting better release after release, and the list of
runnable applications is getting larger. It even runs Word and Excel!
11.2. Using tar and gzip
Under UNIX there are some widely used applications to archive and
compress files. tar is used to make archives---it's like PKZIP or
Winzipbut it doesn't compress, it only archives. To make a new
archive:
$ tar cvf [file...]
To extract files from an archive:
$ tar xvf [file...]
To list the contents of an archive:
$ tar tf | less
You can compress files using compress, which is obsolete and shouldn't
be used any more, or gzip:
$ compress
$ gzip
that creates a compressed file with extension .Z (compress) or .gz
(gzip). These programs can compress only one file at a time. To
decompress:
$ compress -d
$ gzip -d
RMP.
There are also the unarj, zip and unzip (PK??ZIP compatible)
utilities. Files with extension .tar.gz or .tgz (archived with tar,
then compressed with gzip) are as common in the UNIX world as .ZIP
files are under DOS. Here's how to list the contents of a .tar.gz
archive:
$ tar ztf | less
11.3. Installing Applications
First of all: installing packages is root's work. Most Linux
applications are distributed as a .tar.gz archive, which typically
will contain a directory aptly named containing files and/or
subdirectories. A good rule is to install these packages from
/usr/local with the command
# tar zxf
reading then the README or INSTALL file. In most cases, the
application is distributed in source, which you'll have to compile;
often, typing make then make install will suffice. If the archive
contains a configure script, run it first. Obviously, you'll need the
gcc or g++ compiler.
Other archives have to be unpacked from /; this is the case with
Slackware's .tgz archives. Other archives contain the files but not a
subdirectory - careful not to mess things up! Always list the contents
of the archive before installing it.
Debian and Red Hat have their own archive format; respectively, .deb
and .rpm. The latter is widely used by many distributions; to install
an rpm package, type
# rpm -i package.rpm
11.4. Tips You Can't Do Without
Backscrolling: pressing (the grey key) allows you to
backscroll a few pages, depending on how much video memory you have.
Resetting the screen: if you happen to more or cat a binary file, your
screen may end up full of garbage. To fix it, blind type reset or this
sequence of characters: echo CTRL-V ESC c RETURN.
Pasting text: in console, see below; in X, click and drag to select
the text in an xterm window, then click the middle button (or the two
buttons together if you have a two-button mouse) to paste. There is
also xclipboard (alas, only for text); don't get confused by its very
slow response.
Using the mouse: if you installed gpm, a mouse driver for the console,
you can click and drag to select text, then right click to paste the
selected text. It works across different VCs.
Messages from the kernel: have a look at /var/adm/messages or
/var/log/messages as root to see what the kernel has to tell you,
including bootup messages. The command dmesg is also handy.
11.5. Where to Find Applications
If you're wondering whether you can replace your old and trusted
DOS/Win application with a Linux one, I suggest that you browse the
main Linux software repository: .
Other good starting places are the ``Linux Applications and Utilities
Page'' , the ``official''
Linux page , and .
11.6. A Few Things You Couldn't Do
Linux can do an awful lot of things that were cumbersome, difficult or
impossible do to with DOS/Windows. Here's a short list that may whet
your appetite:
· at allows you to run programs at a specified time;
· awk is a simple yet powerful language to manipulate data files (and
not only). For example, being data.dat your multi field data file,
$ awk '$2 ~ "abc" {print $1, "\t", $4}' data.dat
prints out fields 1 and 4 of every line in data.dat whose second field
contains ``abc''.
· cron is useful to perform tasks periodically, at specified date and
time. Type man 5 crontab.
· file tells you what filename is (ASCII text, executable,
archive, etc.);
· find (see also Section ``Directories: Translating Commands'') is
one of the most powerful and useful commands. It's used to find
files that match several characteristics and perform actions on
them. General use of find is:
$ find
where includes search criteria and actions. Examples:
$ find . -type l -exec ls -l {} \;
finds all the files that are symbolic links and shows what they point
to.
$ find / -name "*.old" -ok rm {} \;
finds all the files matching the pattern and deletes them, asking for
your permission first.
$ find . -perm +111
finds all the files whose permissions match 111 (executable).
$ find . -user root
finds all the files that belong to root. Lots of possibilities
here---RMP.
· grep finds text patterns in files. For example,
$ grep -l "geology" *.tex
lists the files *.tex that contain the word ``geology''. The variant
zgrep works on gzipped files. RMP;
· regular expressions are a complex but darn powerful way of
performing search operations on text. For example, ^a[^a-
m]X{4,}txt$ matches a line that starts with `a', followed by any
character except those in the interval a-m, followed by 4 or more
`X', and ends in `txt'. You use regular expressions with advanced
editors, less, and many other applications. man grep for an
introduction.
· script dumps the screen contents on script_file until
you issue the command exit. Useful for debugging;
· sudo allows users to perform some of root's tasks (e.g. formatting
and mounting disks; RMP);
· uname -a gives you info about your system;
· zcat and zless are useful for browsing and piping gzipped files
without decompressing them. For example:
$ zless textfile.gz
$ zcat textfile.gz | lpr
· The following commands often come in handy: bc, cal, chsh, cmp,
cut, fmt, head, hexdump, nl, passwd, printf, sort, split, strings,
tac, tail, tee, touch, uniq, w, wall, wc, whereis, write, xargs,
znew. RMP.
11.7. Practicing UNIX under DOS/Win
Believe it or not, there are fine tools that provide a UNIX-like
environment under DOS/Windows! One is the Djgpp suite (
) for DOS, while Cygwin (
) is a more complex port for Win32. Both
include the same GNU development tools and utilities as Linux; you
won't get the same stability and performance, though.
If you'd like to have a taste of Linux, try out Djgpp. Download and
install the following files (as of this writing, the latest version is
2.02): djdev202.zip, bnu281b.zip, bsh1147b.zip, fil316b.zip,
find41b.zip, grep22b.zip, gwk303b.zip, lss332b.zip, shl112b.zip..
Installation instructions are provided, and you can find assistance on
.
In particular, using bash under DOS/Win is a whiff of fresh air. To
configure it properly, edit the supplied file BOOT.BAT to reflect your
installation, then put these files in your home directory (in the
Windows partition) instead of those provided:
# this is _bashrc
LS_OPTIONS="-F -s --color=yes"
alias cp='cp -i'
alias d='ls -l'
alias l=less
alias ls="ls $LS_OPTIONS"
alias mv='mv -i'
alias rm='rm -i'
alias u='cd ..'
# this is _bprof
if [ -f ~/_bashrc ]; then
. ~/_bashrc
fi
PS1='\w\$ '
PS2='> '
CDPATH="$CDPATH:~"
# stuff for less(1)
LESS="-M-Q" # long prompt, silent
LESSEDIT="%E ?lt+%lt. %f" # edit top line
VISUAL="jed" # editor
LESSCHARSET=latin1 # visualise accented letters
export PS1 PS2 CDPATH LS_OPTIONS LESS LESSEDIT LESSOPEN VISUAL LESSCHARSET
11.8. Common Extensions and Related Programs
You may come across scores of file extensions. Excluding the more
exotic ones (i.e. fonts, etc.), here's a list of who's what:
· 1 ... 8: man pages. Read them with groff -Tascii -man .
· arj: archive made with arj.
· dvi: output file produced by TeX (see below). xdvi to visualise it;
dvips to turn it into a PostScript .ps file.
· gz: archive made with gzip.
· info: info file (sort of alternative to man pages). Get info.
· lsm: Linux Software Map file. It's a plain ASCII file containing
the description of a package.
· ps: PostScript file. To visualise or print it get gs and,
optionally, ghostview or gv.
· rpm: Red Hat package. You can install it on any system using the
package manager rpm.
· taz, tar.Z: archive made with tar and compressed with compress.
· tgz, tar.gz: archive made with tar and compressed with gzip.
· tex: text file to submit to TeX, a powerful typesetting system. Get
the package tex, available in many distributions.
· texi: texinfo file, can produce both TeX and info files (cp.
info). Get texinfo.
· xbm, xpm, xwd: graphic file.
· Z: archive made with compress.
11.9. Converting Files
If you need to exchange text files between DOS/Win and Linux, be aware
of the ``end of line'' problem. Under DOS, each line of text ends with
CR/LF (that is, ASCII 13 + ASCII 10), with LF under Linux. If you edit
a DOS text file under Linux, each line will likely end with a
strange--looking `M' character; a Linux text file under DOS will
appear as a kilometric single line with no paragraphs. There are a
couple of tools, dos2unix and unix2dos, to convert the files.
If your text--only files contain accented characters, make sure they
are made under Windows (with Notepad) and not under plain DOS;
otherwise, all accented characters will be screwed up.
11.10. Free Office Suites
Yes, you can have for free what would otherwise cost a lot of money!
StarOffice ( .) is currently the only
choice, though Koffice is down the pipeline (
). StarOffice is big and slow, but very good
anyway: it offers a lot of functionality not found in Microsoft
Office. It can also read and write Word and Excel files, although the
conversion isn't always perfect.
Another good package is Corel WordPerfect, a free edition of which is
available for download. Need I say more? Go fetch it:
.
12. The End, for Now
Congratulations! You have now grasped a little bit of UNIX and are
ready to start working. Remember that your knowledge of the system is
still limited, and that you are expected to do more practice with
Linux to use it comfortably. But if all you had to do was get a bunch
of applications and start working with them, what I included here is
enough.
I'm sure you'll enjoy using Linux and will keep learning more about
it---everybody does. I bet, too, that you'll never go back to DOS/Win!
I hope I made myself understood and did a good service to my 3 or 4
readers.
12.1. Copyright
Copyright (c) by Guido Gonzato, ggonza at tin.it. This document may be
distributed only subject to the terms and conditions set forth in the
LDP License at , except that
this document must not be distributed in modified form without the
author's consent.
If you have questions, please refer to the Linux Documentation Project
home page,
12.2. Disclaimer
This document is provided ``as is''. I put great effort into writing
it as accurately as I could, but you use the information contained in
it at your own risk. In no event shall I be liable for any damages
resulting from the use of this work.
Many thanks to Matt Welsh, the author of ``Linux Installation and
Getting Started'', to Ian Jackson, the author of ``Linux frequently
asked questions with answers'', to Giuseppe Zanetti, the author of the
book ``Linux'', to all the folks who emailed me suggestions, and
especially to Linus Torvalds and GNU who gave us Linux.
Feedback is welcome. For any requests, suggestions, flames, etc., feel
free to contact me.
Enjoy Linux and life,
Guido =8-)